Search Publications
The X Persei system in the ROSAT all-sky survey.
Mavromatakis, F.
We report the analysis of soft X-ray data from the X-ray pulsar 4U 0352+30, taken by the ROSAT satellite. The mean luminosity, in the ROSAT bandpass (0.1-2.4 keV), is 6 × 1O33 d2kpc erg s-1 and is consistent with that usually seen in the soft X-ray band. The energy spectrum can be described by a flat pow…
On the momentum balance along the comet Halley-Sun line during the Giotto flyby
Neubauer, F. M.; Israelevich, P. L.; Ershkovich, A. I.
The plasma velocity along the Sun-comet Halley line is derived by using in situ measurements of the magnetic field along the Giotto trajectory. Including this velocity profile in the momentum balance turns out to be insufficient in order to support the magnetic barrier with conventional parameters of ion-neutral interaction. The observed magnetic …
High-Speed Ultraviolet Photometry of HD 60435
Dolan, J. F.; Nelson, M. J.; Percival, J. W. +5 more
We present the first high-speed ultraviolet photometry of an oscillating Ap star, HD 60435. After removing known orbital effects related to the Hubble Space Telescope, we confirm the presence of a strong pulsation period at a frequency of 123.70 cycles per day. In addition, we find significant amplitude modulation of this frequency that we suggest…
The Ulysses Cosmic Ray Isotope Experiment I: Source Abundances of C, N, and O Derived from High Resolution Measurements
Simpson, J.; Connell, J.
Upper limits to Jovian hard X radiation from the Ulysses gamma ray burst experiment
Hurley, K.; Sommer, M.; Waite, J. H.
We describe the first in situ search for Jovian X radiation with a dedicated X ray instrument. Upper limits to Jupiter's X ray power in the 27-48 keV range are presented using data taken by the gamma ray burst experiment on the inbound Ulysses trajectory, at distances between 163 and 110 RJ. The data were analyzed using three methods fo…
A development of double star astronomy after Hipparcos
Lampens, P.; Dommanget, J.
Now that the HIPPARCOS satellite safely revolves on his 'degraded' orbit - after the exploit of the ESA technicians to rescue it from the faulty ignition of its apogeum boost motor - and regularly provides the information needed for reaching the initial aim of the project, one may turn to examine the possible applications of the finalHipparcos Cat…
The low-frequency interplanetary radiation
Kurth, W. S.
Observations of the low-frequency interplanetary radiation have continued, although no major activity has begun since mid-1991. Theoretical work has been completed which suggests that the long-speculated source at the termination shock is feasible and could at least qualitatively account for several aspects of the observations, although some diffi…
Initial results from the solar flare X-ray observations with ulysses
Hurley, K.; Sommer, M.; Kane, S. R. +1 more
The Solar X-Ray/Cosmic Gamma-Ray Burst Experiment aboard the Ulysses spacecraft measures hard X-ray spectra in the nominal energy range 15-150 keV, which can be changed by ground command. Since the experiment turn-on on 11 November 1990, it has recorded hard X-ray emission from ~100 solar flares of GOES soft X-ray class > M and several hundred …
The COS-B X-ray observations of X-ray binaries.
van der Klis, M.
The observational information on X-ray binaries that was collected with the 80 sq cm auxiliary X-ray detector onboard the COS-B gamma-ray satellite is reviewed. The results illustrate that in the study of X-ray binaries observations of long duration are extremely effective, even when using a small instrument.
Activity in late-type stars. IX. The weakest chromosphere M dwarf yet discovered : GL 105B.
Byrne, P. B.
We present an estimate of chromospheric radiative losses from the dM(e) star, Gl 105B, based on a measurement of the MgII h&k emission line flux, which indicates that this star has the weakest chromospheric heating rate yet found in any M dwarf and that it lies well below the 'basal' heating rate of derived by Schrijver (1987).